[Homeopathy in headaches. A review].

Homeopathy as an alternative to conventional therapy is becoming increasingly popular. Although interest is rising, little is known about the real effectiveness of homeopathic therapy in headaches. Three studies addressing this question are discussed: an Italian migraine study, the London migraine study and our own, the Munich headache trial. While the first one reported very high effects, the best ones known in the literature, the results of the other two trials do not endorse this first finding. The London trial did not show any effect other than placebo, although a different time trend was reported. The Munich study failed to show any difference between homeopathy and placebo whatsoever. The merits and shortcomings of these studies are discussed. At present, we do not have any evidence that homeopathic therapy has any effect other than a placebo effect. However, this can be very impressive sometimes. We do not know which variables are correlated with placebo effectiveness, and we do not have any data on real-type homeopathy outside a trial setting, as there are no data available.